Britain's Queen Elizabeth II takes part in the Remembrance Sunday service at the Cenotaph in London, Sunday, Nov.13, 2016. (AP Photo/Alastair Grant)

LONDON (AP) — Queen Elizabeth II led the royal family, political leaders and veterans in a solemn service to honor Britain’s war dead Sunday, as Britons across the nation paused for a moment’s silent reflection to mark Remembrance Sunday.

The monarch laid the first wreath of red poppies at the foot of central London’s Cenotaph war memorial in an annual service to remember all those killed in past and present conflicts.

A hush fell over the capital as those gathered observed a two-minute silence at 11 a.m. to commemorate the end of World War I on Nov. 11, 1918 — when guns on the Western Front fell silent on the 11th hour of the 11th day of the 11th month. Remembrance Sunday is held each year on the second Sunday in November.

Later, crowds lining the streets of Whitehall cheered as some 8,500 veterans and servicemen and women marched past to music played by military bands.

Remembrance events this year are especially poignant because 2016 marks the centenary of the Battle of the Somme and the Battle of Jutland. The British Army suffered almost 60,000 casualties on the first day of the Somme battle alone, and more than a 1 million men would be killed or injured on both sides over the course of the offensive.

Britain holds great importance in paying tribute to those who fought in the two World Wars as well as the thousands killed or injured in conflicts since 1945.

Prime Minister Theresa May said this year’s tribute should also be a time to remember British forces fighting the Islamic State group, those combating piracy or taking part in peacekeeping efforts in Africa.